The following relates to a warning system which is particularly suitable for use in a situation in which personnel are exposed to moving machinery.
The invention is described hereinafter with reference to its application in a mining environment but this is by way of example only for the principles of the invention are applicable to other situations and installations.
In an underground location in a mine, personnel are often exposed to moving mining machinery. Large machines are used for mining-related tasks and, typically, each machine is controlled by an operator who sits in a cabin on the machine or who controls the machine via a remote control arrangement. The operator's field of view in the vicinity of the machine can be severely restricted and, in addition, due to environmental factors such as poor visibility, noise and rough terrain it can be extremely difficult for an operator to be aware of the presence of personnel in the vicinity of the machine. These machines can thus pose a serious safety threat to humans and, unfortunately, serious injuries and deaths do occur.
U.S. Pat. No. 4,937,795 describes an alarm system which operates at ultrasonic frequencies and which addresses some of the aforementioned issues. However the system is directional in nature and offers limited application.
Thus, there is a need to provide a system which, at least partly, addresses the aforementioned situation.